Book Image

Learning Scala Programming

By : Vikash Sharma
Book Image

Learning Scala Programming

By: Vikash Sharma

Overview of this book

Scala is a general-purpose programming language that supports both functional and object-oriented programming paradigms. Due to its concise design and versatility, Scala's applications have been extended to a wide variety of fields such as data science and cluster computing. You will learn to write highly scalable, concurrent, and testable programs to meet everyday software requirements. We will begin by understanding the language basics, syntax, core data types, literals, variables, and more. From here you will be introduced to data structures with Scala and you will learn to work with higher-order functions. Scala's powerful collections framework will help you get the best out of immutable data structures and utilize them effectively. You will then be introduced to concepts such as pattern matching, case classes, and functional programming features. From here, you will learn to work with Scala's object-oriented features. Going forward, you will learn about asynchronous and reactive programming with Scala, where you will be introduced to the Akka framework. Finally, you will learn the interoperability of Scala and Java. After reading this book, you'll be well versed with this language and its features, and you will be able to write scalable, concurrent, and reactive programs in Scala.
Table of Contents (21 chapters)
Title Page
Packt Upsell
Contributors
Preface
Index

Tail call optimization


We are familiar with the limitations recursion brings with it. We are aware that each function call, if not tail recursive, builds a new stack frame. For scenarios where we have to deal with a large number of function calls, this could possibly result in a stack overflow, which is undesirable. So, what's suggested in this kind of scenario is to make the recursive function call the last statement in your function definition, the Scala compiler then does the rest for you. Take a look at the following:

import scala.annotation.tailrec

object TailRecursion { 
  def main(args: Array[String]): Unit = { 
      val list = List("Alex", "Bob", "Chris", "David", "Raven", "Stuart") 
    someRecursiveMethod(list) 
 
  } 
 
  /* 
      You have a sorted list of names of employees, within a company. 
      print all names until the name "Raven" comes 
  */ 
  @tailrec 
  def someRecursiveMethod(list: List[String]): Unit = { 
      list match { 
        case Nil => println("Can...